One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,4)(5,6)(7,9)(8,10)(11,12)(13,14,19,17)(15,22,24,28)(16,21,18,25)(20,27,26,23)(5,6)(7,11)(8,10)(9,12)(13,15)(14,20)(16,23)(17,26)(18,27)(19,24)(21,28)(22,25) involution — undirected(2,4)(5,7,8,12)(6,9,10,11)(13,16,19,18)(14,21,17,25)(15,23,24,27)(20,28,26,22)(7,12)(9,11)(13,17,19,14)(15,22,24,28)(16,25,18,21)(20,27,26,23)(6,10)(9,11)(15,24)(20,26)(22,28)(23,27) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.